drm/i915/tv: Use intel_flush_display_plane() to flush the primary plane

Instead of writing to the DSP_ADDR ourselves. This will do the right
thing on gen >= 4 as well.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_tv.c

@@ -1088,13 +1088,11 @@ intel_tv_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 		int dspcntr_reg = DSPCNTR(intel_crtc->plane);
 		int pipeconf = I915_READ(pipeconf_reg);
 		int dspcntr = I915_READ(dspcntr_reg);
-		int dspbase_reg = DSPADDR(intel_crtc->plane);
 		int xpos = 0x0, ypos = 0x0;
 		unsigned int xsize, ysize;
 		/* Pipe must be off here */
 		I915_WRITE(dspcntr_reg, dspcntr & ~DISPLAY_PLANE_ENABLE);
-		/* Flush the plane changes */
-		I915_WRITE(dspbase_reg, I915_READ(dspbase_reg));
+		intel_flush_display_plane(dev_priv, intel_crtc->plane);
 
 		/* Wait for vblank for the disable to take effect */
 		if (IS_GEN2(dev))
@@ -1123,8 +1121,7 @@ intel_tv_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 
 		I915_WRITE(pipeconf_reg, pipeconf);
 		I915_WRITE(dspcntr_reg, dspcntr);
-		/* Flush the plane changes */
-		I915_WRITE(dspbase_reg, I915_READ(dspbase_reg));
+		intel_flush_display_plane(dev_priv, intel_crtc->plane);
 	}
 
 	j = 0;